Improvement in dental engines



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Patented Sept. 2, 1879.

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E.' T. STARR. Dental-Engine.

Patexted Sept. 2, 1879.

No. 219,320.v

WI YN'LUSSJfS N.PETERS. PHcTo-LITHOGRAPHER. WASHINGTON. D C.

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E. T. STARR. Dental-Engine.

Patented sept. 2.1879.

WITNESSS UNITED STATESPATENI' OFFICE.

ELI T. STARR, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO SAMUEL S.WHITE, OF SAME PLAGE.

IMPROVEMENT IN DENTAL ENGINES.

g Specification forming part of LettersPatent No. 219,320: datedSeptember 2, 1379; LPPICILOD filed June 17, 1879.

To all whom it may concern Be it known that I, ELI T. STARR, of the cityand county of Philadelphia, in the State of Pennsylvania, have inventedcertain new and useful Improvements in Dental Engines, of. which thefollowing is a specification.

My invention relates more especially to improvements upon the Well-known S. S. White dental engine. That engine embodies in its structurea supporting-base or tripod7 upon which is pivoted an upright armcarrying a flexible driving-shaft, which communicates motion to anoperating-tool, power being imparted to the flexible shaft from afoot-treadle, also mounted on the base. The flexible shaft is envelopedand protected by a exible sheathor cover secured to or projecting fromthe head of the engine-arm, which arm has the capacity of rocking uponthe fixed standard of the base, so as to `give the operating-tool anincreased range of movement over that afforded by the mere flexure ofthe shaft and sheath, the said engine-arm being maintained in anormallyupright position by a counter-balance or spring.

The object of the first part of my present invention is to tilt orincline the base4 and engine-arm so that said'arm will be thrown out ofthe perpendicular, which endI attain by means of a toe pivoted to thebase, and capable of being adjustedto tilt said base and engine-armcarried thereby, or permit the base to rest with the engine-arm in aperpendicular, or substantially perpendicular, or upright position. i

I The object of the `next part of my invention is to tilt or incline thebase and engine-arm in different directions, or to eithervside of theperpendicular, which ends I attain byduplicate tilting-toes pivoted tothe base upon different sides. n

The object of the next part of my invention isto enable the normalposition of theenginearm to be changed from the perpendicular todifferent angles relatively to the base, while still permitting it torock thereon, which ends I attain by means of a plate connected with acounterbalancing or returning spring acting onwthe rocking arm, theadjustment of said plate varying the normal position of the eugine-armrelatively to the base without destroying its rocking capacity.

The accompanying drawings show a dental engine embodying all my presentimprovements in the best way now known to me. Obviously, however, someof my improvements may be usedA without the others, and in enginesdiffering somewhat in their details of construction from that thereinshown.

Figure 1 is a side elevation of my improved engine, the top portionthereof being broken off and brought down to one side to show the Wholeapparatus; Fig. 2, a view thereof from the back of the engine 5 Fig. 3,a view in section on the line 3 3 of Figs. 1 and 2 5 Fig. 4, a bottomview of one of the arms of the tripod or base; Fig. 5, a longitudinalsection through the same on the line 5 5 of FigAE; Fig. 6, a view of aportion of the standard which rises from the base, the rocking arm, andthe mechanism for varying the normal po sition of said arm, partly insection on the line 6 6 of Fig. 7 5 and Fig. 7, a vertical sectionthrough a portion of the apparatus on the line 7 7 of Fig. 6.

The base, tripod, or stand A is provided with a ixed upright orstandard, a, forming part of the base, the upper end of which is forkedor divided for the reception of the drivin g-pulley B, the journal ortrunnions of which turn in suitable bearings or boxes in said standard,in the usual manner. A driving-crank, b, is attached to one end of thepulley journal or axle, and `is connected by a plate-spring pitman, O,withlthe treadle, pedal, or footboard D, pivoted upon one arm of thetripod, or upon the base, as usual. The forked or divided end of thestandard is also provided outside the pulley with trunnions or pivots alal, for the reception of the forked end of the engine-arm E, which isalso of well-known construction, and carries upon its upperend a drivenpulley and its spindle, to which latter the flexible drivin g-shaft isconnected, as usual. Y v

The flexible shaft or power-conveyer and its envelopingprotecting-sheath, when the latter is used, are of well-knownconstructions, being similar to those employed in the S. S. White dentalengine hereinbefore referred to, and substantially similar to thoseshown in Nelson Stows reissued Letters Patent No. 8,607, of March 4,1879.

In order to give the tripod or base the vcapacity of being tilted orinclined at pleasure in different directions, so as to throw or bring`the head or upper end of the engine-arm in front of or toward thepatient, or out of the perpendicular, irrespective and independently ofits rocking movement upon the base, and without at the same timenecessitating bringing the base or treadle inconveniently close to thepatient or operating -chair, and also in order to incline the pedal,treadle, or footboard D so that it may be operated when the foot isthrown out with ease and comfort, I provide the base or the two arms ofthe tripod opposite 11e portion or arm thereof upon which the treadle ismounted with toes or pivot-pieces A'A, which are acted upon by retainingplatesprings a2 a2, as clearly shown in Figs. 4 and 5, said springsacting to maintain the toes in their adjusted position, whether that bein a position to tilt the base or otherwise.

The toes are pivoted, when the tripod form of base is employed, in theends of the arms or feet of the tripod, so that when thrown out oradjusted in line with said arms the base is permitted to rest squarelyand evenly upon the iioor or supporting-surface, but when moved, rocked,or adjusted inwardly at right angles, or nearly so, to said arms, raisethat portion of the tripod or base to which they are pivoted,consequently tilting or inclining the base, its standard, and theengine-arm with its appurtenances, together with the treadle. The npperend or head of said arm is therefore brought, if the engine is in properposition, toward or in front of the patient, affording great freedom tothe enveloping sleeve or sheath and to the inclosed drivin g-shaft,which is a desideratum of much importance in the perfect working ofdental engines.

It will be obvious that when both the inclining-toes are adjusted totilt the base said base will be tilted in 4the direction of the lengthof the treadle, while by using one only of the toes at a time the basewill be tilted sidewise, whereby I am enabled to incline or tilt thebase and its appurtenaces in different directions, or to either side ofthe perpendicular, as may be desirable or necessary.

To control the rocking movement of the engine-arm upon its pivots orjointing to the base, or to return it automatically to and maintain itin a normal position, various connter-balances have'been employed, thebest form of which I consider to be a spring the tension of which, assoon as the force exerted to deflect or rock the arm is removed, returnssaid arm to its normal position. These returning or counterbalancin gsprings (both spiral and plate) have been applied in various Ways.

In order to enable the normal position of the engine-arm to be variedrelatively to the base or tripod without destroying its rockingcapacity, I employ, in this instance, a plate, F, pivoted at fconcentrically with the rocking arm, and secure to said plate one end ofa spring, G--a plate-spring by preference-the other end of which isprovided with a yoke or loop, g, through which the rocking arm passes,said yoke being the means in this organization by which the spring actsupon the arm. j

The plate Fis provided with a curved slot, f concentric with its pivot,through which a setscrew or locking-bolt, H, passes into a threadedsocket formed in the standard of the base or tripod. By tightening thisset-screw the plate may be locked at any position desired in its rangeof movement around its pivot "permitted by the slot, and consequentlythe angle of the arm varied at pleasure, which angle will be the normalposition ofthe rocking arm, inasmuch as it will be so maintained by thespring, and automatically returned, when deflected, to that position bythe force or tension of said spring.

By the construction and organization above described I am enabled tosecure the platespring, which retains the rocking arm in its normalposition, to thc base, while allowing it to act upon said' arm above thebase, thereby avoiding the necessity of extending the enginearm, or aportion thereof, below its pivots, to be acted upon by the spring, andfurthermore obtain a compact arrangement of parts.

rIhe branch of the forked rockingarm E neXt the adj Listing-plate F, itwill be observed, is provided below its pivot with depending ears orlugs c e, which overlap or pass down upon both sides of the uppercontracted portion of said plate, which construction is for the purposeof limiting the range of movement of the rocking arm, no matter in whatnormal -position it may be, owing to the adjustmentof the plate,inasmuch as said lugs come in contact, when the arm is' rocked upon itspivots, with the sides of the plate, which plate is firmly fastened tothe standard of the base by its securing device.

I wish it to be understood that I do not herein claim, broadly, thecombination of an. engine-base, an engine-arm, and a device forinclining or tilting said base, as that subjectmatter forms part of myapplication for Letters Patent of the United States filed February 1,1879, of which application this present one is a division. Nor do I wishto be under- 4stood as claiming, broadly, the combination of thedental-engine base, its rocking arm, and mechanism for varying thenormal position of the rocking arm, as thatl subject-matter also formspart of my application of February 1, 1879, above referred to. Nor do Iclaim herein, broadly, the combination cfa tilting base with anengine-arm capable of being set at different angles relatively to thebase; nor the combination, broadly, of a dental-engine base, anengine-arm, and mechanism for changing the normal position of said armWhile still permitting it to `rock or vibrate, the two lastrecitedcombinations also constituting` part of the subject-matter of `my saidapplication filed February l, 1879. I claim herein, as far as thesubject-matter above disclaimed is concerned, only the particularinstrumentalities and organizations of devices hereinbet'ore described,and shown in the accompanying drawings. A

What I claim herein as of my own invention isi 1. The combination,substantially as hereinbefore set forth, oi' the base, the en gine-arm,and the duplicate inclining or tilting toes, which permit the base andengine-arm to be tilted or inclined in different directions.

2. The combination, substantially as hereinbefore set forth, of the baseor tripod with the pivoted toe, to incline it and the enginearm carriedthereby.

3. rIhe combination, substantiallyT as hereinbefore set forth, of thebase or tripod, its inclining-toe, and the spring to maintain said toein its adjusted position.

4. The combination, substantially as `hereinbefore set forth, of thebase or tripod, the engine-arm, the treadle mounted upon the base, andthe inclining-toes to tilt said base, arm, and treadle.

5. The combination, substantially as hereinbefore set forth, of thebase, its rocking arm,

the plate and its locking` device for varying the normal position of therocking arln While still permitting it to rock, and thecounterbalancing-spring, connected at one end with said plate and at theotherwith the enginearm.

6. The combination, substantially as here- `inbefore set forth, of thebase, therocking arm, the flexible shaft connected with the rocking arm,the, adjustable plate for varying the normal position of said arm, andthe spring connected Wit-l1 the adjustable plate at one rocking arm, thepivot of which is coincident With the pivots of the engine-arm, and thelocking device to secure said plate to the i base.

8. The plate-spring secured atone end to the engine-base, and providedat the other with a loop or yoke, through which the rocking arm passes.

9. The combination, substantially as hereinbefore set forth, of thebase, the forked e11- gine-arm pivoted thereon, and the ears or lugsupon said arm to limitits range of movement.

10. 'Ihe combination,'substantially as hereinbefore set forth, `of thebase, the engine-arm rocking thereon, mechanism for varying the normalposition of said arm, lugs or devices for limiting the range of rockingmovement of the arm, and the spring acting upon the arm.

11. The combination, substantiallyas hereinbefore set forth, of thebase, its inelining devices, the'treadle, the rocking` engine-arm, andthesprin g to keep `said arm in its normal position.

12. The combination of the base, the engine-arm, the inclining device ofthe base and arm, the device for varying the normal position of saidarm, and the returning-spring, which permits the arm to rock, Whatever'may be its normal position as determined by the adj usting mechanism. g

l-n testimony whereof I have hereunto subscribedmy name.

ELI T. STARR.V

Witnesses:

GEORGE P. MORGAN, ALBERT I. Itoo'r.

